Hydraulic torque actuator



Jan. 19, 1965 J. H. TAYLOR HYDRAULIC TORQUE ACTUATOR 2 Sheets-Sheet 1 Filed June 1, 1961 11 N m P um v S 2. a 0 O T a mm mq e 5Q mm mm a S fl s I mu 3 2 5 mm mm 3 3 E 8 m 5 Q 3 2 mm 8 8 N 3 h S 2/ Q i 3 m N\ m on S m AB 0 m 2 a 3 VN m INVENTOR Jan. 19, 1965 J. H. TAYLOR HYDRAULIC TORQUE ACTUATOR Filed June 1, 1961 2 Sheets-Sheet 2 INVENTOR fi- K.

United States Patent 3,165,982 HY-DRAULEC TQRQUE ACTUATGR John H. Taylor,.% (Iauadian Research 8: Development Foundation, 1437 Van Horne Ave, Lachine, Quebec,

Canada a Filed June 1, 1961, Ser. No. 114,136 Claims. (Ci. 92-33) This invention relates to improvements in hydraulic mechanisms and more particularly to improvements in hydraulic torque actuators.

It is conventional practice to utilize hydraulic pressure in the actuation of devices requiring a large amount of torque such as, for instance, aircraft flaps or the like. The conventional method of utilizing hydraulic power in this respect is by means of a hydraulic jack incorporating a piston and jack ram, the jack ram being caused to move inwardly or outwardly of the jack depending on the side of the piston to which the hydraulic pressure is applied, and this reciprocal action of the jack ram is transmitted through an arcuately operating lever to cause the flap or the like to 'move through an arc of, usually, 90".

The disadvantages of this conventional system are that the jack must pivot during the operation and therefore, may be pivotally attached to the surrounding structure at ice seal in direct contrast to a hydraulic jack in which the seal must necessarily move with the piston.

These and other objects and features of this invention will become apparent when taken in conjunction with the accompanying drawings in which:

FIG. 1 is a mid vertical sectional side elevation of a hydraulic torque actuator embodying this invention.

one end only. The jack ram also may become contaminated with sand or the like while in the extendedposition and, upon being retracted, this sand destroys the seal and permits hydraulic fluid to leak from the jack.. An additional disadvantage lies in the fact that the lever attached to the flap or the like requires a-large amount of space v human error, may not be properly secured and may thus Referring to FIG. 1, a torque actuator 10 comprises a cylinder assembly 11, a piston assembly 12 and a torque shaft 13. Cylinder assembly 11 comprises two open ended cylinders 14 and 15 in axial alignment, .the open end 16 of cylinder 14 bearing a flange 17 adapted to extend both internally and externally of cylinder 14. Cylinder 15 carries a similar flange 18 at its open end 19. Flange 17 of cylinder 14 and flange 18 of cylinder 15 are adapted to be joined substantially in face to face relation-,.

ship by-conventional means, such as for instance, bolts. An outwardly facing annular recess 20 is formed at the inner-edge of flange 17 and a similar recess 21 is formed in'flange 18, recesses 20 and 21 being adapted to house two oppositely facing V-type sealing rings 22 and 23 re-. spectively, V-ring 22 being adapted to prevent fluid escape from the bore of cylinder 14 and V -ring 23 being adapted to prevent fluid escape from the bore of cylinder 15. An' annular-plate 24 is interposed between rings 22 and 23 and sealably recessed into theouter surfaces of flanges 17 and 18 ofcylindersl l and 15 respectively, plate 24 i being adapted to provide a rigid structure for the outerendanger the aircraft and crew. Also, upon being used to operate aircraft flyingc'ontrols or the like, thecomplete mechanism is extremely diflicult to streamline. Furthermore, due to the arcuate movement of the jack body, the pipelines conducting the hydraulic fluid to and from the jack must necessarily be flexible causing them to be far more difficult to manufacture and more prone to leak n a another object r this invention a providfa hydraulic torque actuatorjwhich .may be rigidly aflixcdto It is stillanother object of this invention toprovide a the structure adjoining the mechanism to be rotated.

hydraulic torque actuator which will eliminate-pivot pins-f and the like ,by'being keyed directly to the hub of the mechanism to be actuated. V a

It is a further object of this invention to provides, hy-

draulic torque actuator which maybe supplied with hydr'aulic fluid through rigid pipelines, thereby cut-ting down a the cost of installation and lowering the possibilityof I It is yet another object of this invention to provide 2 pipeline leakage;

hydraulic torque actuator which may be completely streamlined in thesmallest possible space due to the fact that the actuator body does not move. during operation.

"It is still another object of this invention to provide a hydraulic. torque actuator which mayhavethe operating shaft thereof caused to rotate through any'd'esired number of degrees during afsingle stroke of the operating piston.

' It is yet another object ofthisinventionto provide' a' hydraulic torque actuator in whichinternal, wear-and V leakage is minimized by means of utilizing a static piston most surfaces of rings 22 and 23 and to support them wardly-of end wall 25 to be supported .in a block 27 formed centrally on the outer surface of end wall 25, bush 26 being adapted to rotatably support one end 28 of'torque shaft 13. An end cover plate29 is s'ealably fitted over the outer'surface of block 27 by conventional 'n'reans, such'as for'instance, screws. ;j a

v end'30 of shaft. 13 similarly {passes through an end wall 31 offcylinder 15 and issimilarly supported by a bush 32 located within ablock' 33', and

due to end of shaft 13 extending outwardly beyond j block 33, a -ring type seal 35. isjhoused'in .a convert j 1 tional manner within block 33 and retained therein by end The opposite plate 34.

It should be soadnaenasija and assigns-1 are of reduced diameter therebygforming two oppositelylo l,

catedshoulders 36 and 37-respectivelyl -on shaft 13. A

' ball thrust bearing 38 is fittedoverend Z-S 'of! shaft 13"." j and isadapted to absorb axial pressure exerted on shaft'i 13 between shoulder 36 of shaft'13 and the inner surface}; of end wall 25 of cylinder 14. Similarly, a thrust bearing 39is -located'betwe en shoulder 37 and the innerfsur- 1 face of end wallfil of cylinderli to absorb axial pressure in the opposite direction.

'A conventional hydraulic fitting ill passes through i wall 25 of cylinder 14 to' permit hydraulicTfluid' under pressure to be supplied to'cylinder 14, asirnilar ghydraulic fitting 41 is located through end wall'3j1 offcylindei' 15-j 7 to supply hydraulic fluid tO theIinterior ofjcylinder fl i.

Referring to FIGS. 1 and 3, pistonassemblyllcom 1 prises an inner cylinder45 and' an puter'cylirideidd, 1: cylinders 45 and .46 being coaxial with shaft 13. Inner: "I cylinder 45' is slidably mounted on shaft 13 by means of r 61 respectively. 1

- and end'wall 55 to-preventlealrage therebetween, I q i" Rietefringito FIG. 2, twogsubsjtantially. semi-cylindrical "portions 69 and 7 T are ldcated longitudinally cyl; 'ind'er 15,.tlreir adjacent.longitudinaledges beingin paral? lel spaced. apart relationship thereby forming slots (g2 and} gReferring to FI Ggl, the fulloperatlon o v V fas flfollorvszjFro ni the position.as jillustrateg fiuid under pressure may be permittedlfojenter. cylinder 14 through hydraulic'fitting'tlfand, by means of suitablel valviiig, fluid contained. within .cylinder, 15 is permitted'ito return g to, the reservoir of the -h'y'draulic "circuit, i and therefore;

; fluid pressureiacting on'erid wall 65 of -pist on;fass enably "llcauses piston assembly -12 to move longitudinally into n Shaft :islgthereby caused;tofrotateas' previously; described. jPi essure leakage fronrcylinder'l into cylinder .15-is prevented'by. V ring 2 2 on w alls; 64L

of outer. cylindendo; -.'.Sirnilarly,; pressure leakage aroundf. f'shaft 13..is preye r aby doubleseal assembly 66p 5: An .opposite' selecticn,of the hydraulic valve assembly 1 cylinder bushes 53 and 54 respectively; spools 55 and 56extending radially outwardly, diametrically oppositely, froma collar 57 which forms ail-integral part of shaft 13 and is locatedsubstantially centrally thereon. A bolt 44 passes through spool 56 and diametrically through collar 5'7 to; threadablyengage spool 55 thereby retaining spoolsSS' and 56 with their respectivebushes 53 and 54 substantially integrally with shaft. 13.

wall thereof and :wall 65 of piston assembly'12 and therefore, piston assembly 12 is caused to move out of cylinderfld and into cylinder 14 and shaft 13 thereby caused to rotate and return to its original position. Pressure leakage from cylinder 15 into cylinder'14 is prevented bythe action of V-ring 23 on walls 64 of outer cylinder 46. Furthermore, any tendency for fluid to leak 'fromwithin piston assembly 12 into cylinder 14 along shaft 13 is prevented by i double seal assembly 66. O-ring 68 also effectively prevents leakage between themating surfaces of end block 47 of inner cylinderj45 and end wall 65 of outer cylinder Referring to- FIGS/1 and 2, it maybe notedthat two 7' bolts 58 and 59 are diametrically oppositely located in, and extend radially outwardly from, block 48 within the rotatably support two double bushing assenibliesfifi and Double bushing assemblies 6%) and 61'are adapted to cooperate within two straightlongitudinal slots (zZand 63 respectively formed within the inner surface of-cylin-. de'r and'extending for the full length. thereof The function of the foregoing mechanismfis to permit :inner cylinder 45 of piston assembly 12 to reciprocate with -in cylinder-assembly Hand to eliminate any tendency to ro'tatethereinp 1 7 v V bore of cylinder 15, bolts 58'a nd 59 being adapted to It should benoted that in the translation of reciprocal movement of piston assembly 12 into rotation of, shaft;

13, the forces acting on shaft 13, throughtbolt 44 and. f

its associated bush and spool -assen1blies,.rnay be resolved into lateral and longitudinal components. The lateral force determines thefarnount of torque developed by shaft 13, the longitudinal force merely applying a nonuseful, axialfthrustto shaft 13. Thrust bearings li andv 39; in conjunction with shoulders36 and 37 respectively, are adapted to prevent axial travelof shaft 13 and. minimine-friction between shaft 13 and end walls/ and 31 of cylinders 14 and 15 respectively.- 1

'drive method maybe incorporated therewith, so that,

'It may be seen, therefore, that reciprocation jorc iin- 'der' causes slots 51 and 52 "formed therein tornoye past bushes 53 and54-on spools 55 and56. In thisfmamner; bushes 53 and 54 are forced to follow thecontour'of;

shaft 13 to rotate.

. slots 51 and 52, and through bolt 44Qand collarj57, cause Outer cylinder 45v is provided to furnisha fluid proof barrier. between the bores of cylinders 14 and 15,10

achieve .thisend, thej'walls 64 of cylinder ddare in perrespectively, thus'permitt in'g piston assembly 12 to move the interior:dflcylinder ldp V 1 Arr O;ring 68;.isalso. located between end 1 block *4 June was sli'dably.'alo ng shaft 13 whilefpreserving the fluid tightfintegrity, between the interior of piston assembly uponsbeing attaciiedto the centre of a flap or the like,

the flapnlay be caused to rotate.

It-rnay be seen that the effectiverange of rotationot shaft 13. is determined bytthe number of convolutions formed by slotsSl and 52 in-inner cylinder {15 of piston assembly. 121 1 nshould'the desired degreel'oif' rotation of shaft 13 be.

suchthafslots 51- and Slate required to be too steeply sloped fslots szgandjes'm cylinder,15 ,may also be anguf .larly 'dispose'dfinjasimilat manner to slots '51. and 52.- This ,csusemhe whole of piston assembly .12 to rotate 40.

to lshaft' 13.".Slots 51fand 52 may,'.there fore, remain at' during itsgline'ar travel, thereby imparting added movement a a lesser-angle and still the desired extra degree of rotation;

vention as-expljained above. may be varied accordingto requirements in ,regards. to manufacture and production thereof, while still. remaining within the spirit. and prina cipl'e'of the.invention, without.prejudicing. the .riovelty 1 .Thefjembodirnents, of the invention in which an exclusive v 1 "property or privilege is"-claim'ed' are defined as, .r f)nqw's; l' l 1 ,A hydraulic. torque actuator. iincluding a .lcylinder assembly,apiston'assernbly and ajtor que shaft; said cylin- 'der assembly comprising a'Tfirst 'cylinderihaving'a'closed J end wall "and anop'enle'nd'and ai'second cylindenhaving closed, end {wall andan open end,'j each of said' openlendsf" I being flangedand said flanges joiniedto unite-said cylin i. ders at their' 'open ends in axial alignmentg -pcripheral sen-.1? qirig meansibetweenjsaid flange-s extensible'finto the bore or said".cylinder assembly; saidpisto'n assembly cor'nprising- 7 integral,pcoaxialfinner and outer hollow cylindrical memcauses arehe'fJpfLpressure froni the interior ofcylin'derf 5 'bers; first and second endwall maintaining said cylindrical members substantially fluid-tight; said piston assembly bet ig axiallyslidablelwithinsaid cylinder assembly, theen d embodying-said first end wall. remaining j within said first cylinder the end opposite'embodying said second end wall remainingwithinsaidsecondifiylinder and the outer surface of said: outericylindrical "member-being in slidable, Q l :Qflu'id tight contact with said peripher al sealingmean's; V

said first cylinder having a. longitudinally f slotted inner.

wall; radial'xtensions froms'aid first; end wallofjsaidfjl outer'cylinjdrical member ofgsaid pistonxassenibly slidablyf' .cooperable with 'saidslott'ed innei ryall to -maintaidsaid;

; piston*assembly in a I predeterminedip ath upon. moving "withinsaid cylinder assembly; said torque shaft extending a,

axially through said cylinder assembly and being sealably and rotatably supported by said closed ends thereof; said torque shaft passing axially through said piston assembly in rotatable, sealed relationship; said inner cylindrical member of said piston assembly being helically slotted substantially throughout the length thereof; spool means extending radially outwardly from said torque shaft slidably cooperable with said helically slotted inner cylindrical member; said torque shaft being in shouldered cooperation with said closed ends of said cylinders to restrain said shaft frorn axial movement while permitting free rotary movement thereof; and adapter means in each of said closed ends of said cylinder assembly to permit the selective ingress and egress of fluid to said first and second cylinders.

2. A hydraulic torque actuator as defined in claim 1, said first cylinder having a plurality of straight, longitudinal slots formed in said inner wall thereof; and said radial extensions having double bushings thereon, closely but freely cooperable within said slots to permit free axial but non-rotatable movement of said piston assembly with in said cylinder assembly. 7 3. A hydraulic torque actuator as defined in claim 1, said first cylinder having a plurality of mutually inclined longitudinal slots formed in said inner wall thereof; and said radial extensions having double bushings thereon, closely but freelycooperable within said slots to permit free axial and controlled rotatable movement of said piston assembly within said cylinder assembly.

4. A hydraulic torque actuator as defined in claim 1,

' said inner cylindrical member of said piston assembly in which at least one end of said torque shaft extends beyond said closed end walls and drive means integral with said shaft end.

References Cited in the file of this patent UNITED STATES PATENTS 623,816 Olsen Apr. 25, 1899 855,256 Morey May 28, 1907 1,741,871 Mitchell Dec. 31, 1929 2,204,649 Barnhart June 18, 1940 3,090,244 Davis May 21, 1963 

1. A HYDRAULIC TORQUE ACTUATOR INCLUDING A CYLINDER ASSEMBLY, A PISTON ASSEMBLY AND A TORQUE SHAFT; SAID CYLINDER ASSEMBLY COMPRISING A FIRST CYLINDER HAVING A CLOSED END WALL AND AN OPEN END AND A SECOND CYLINDER HAVING A CLOSED END WALL AND AN OPEN END, EACH OF SAID OPEN ENDS BEING FLANGED AND SAID FLANGES JOINED TO UNITE SAID CYLINDERS AT THEIR OPEN ENDS IN AXIAL ALIGNMENT; PERIPHERAL SEALING MEANS BETWEEN SAID FLANGES EXTENSIBLE INTO THE BORE OF SAID CYLINDER ASSEMBLY; SAID PISTON ASSEMBLY COMPRISING INTEGRAL, COAXIAL INNER AND OUTER HOLLOW CYLINDRICAL MEMBERS; FIRST AND SECOND END WALL MAINTAINING SAID CYLINDRICAL MEMBERS SUBSTANTIALLY FLUID-TIGHT; SAID PISTON ASSEMBLY BEING AXIALLY SLIDALE WITHIN SAID CYLINDER ASSEMBLY, THE END EMBODYING SAID FIRST END WALL REMAINING WITHIN SAID FIRST CYLINDER, THE END OPPOSITE EMBODYING SAID SECOND END WALL REMAINING WITHIN SAID SECOND CYLINDER AND THE OUTER SURFACE OF SAID OUTER CYLINDRICAL MEMBER BEING IN SLIDABLE, FLUID TIGHT CONTACT WITH SAID PERIPHERAL SEALING MEANS; SAID FIRST CYLINDER HAVING A LONGITUDINALLY SLOTTED INNER WALL; RADIAL EXTENSIONS FROM SAID FIRST END WALL OF SAID OUTER CYLINDRICAL MEMBER OF SAID PISTON ASSEMBLY SLIDABLY COOPERABLE WITH SAID SLOTTED INNER WALL TO MAINTAIN SAID PISTON ASSEMBLY IN A PREDETERMINED PATH UPON MOVING WITHIN SAID CYLINDER ASSEMBLY; SAID TORQUE SHAFT EXTENDING AXIALLY THROUGH SAID CYLINDER ASSEMBLY AND BEING SEALABLY 